Fritz Rabe's thread on smoke and the discussion of animal senses has made me think about this question. Deer are proven to be able to see into the ultraviolet range, and can thus spot clothes washed with normal washing powder, because all of them contain fabric brighteners that make them shine like a "black light" in the old discos in their eyes. For this reason, I wash my hunting clothes separately with non-brightening detergents. They also are unable to see much in color, which is why I like to wear blaze orange camo while hunting (Friendly fire - isn't!). Actually, a good way of testing deer hunting camo is to take black-and-white photos of it in the bush, for that's how the deer see you. It would be interesting to find out if African animals see the same way.